Method of managing a code identifying a wireless device with conflict minimized in a wireless telecommunications system

ABSTRACT

In one wireless device, when wishing to participate in a communications network, an ID generator in an ID manager uses a hash function on the address of the device and time to generate a device identification identifying the one device, and registers the identification on a list storage. In the one wireless device, a list updater stores an identification of another device from a beacon signal into the list storage in association with the address of the other device. When a conflict determiner detects a conflict of device identifications, an ID searcher searches the list storage for an unused identification having a relationship with the conflicting identification according to a relation in magnitude between the addresses of the one and other devices. An ID updater updates the identification of the device in the list storage to the unused identification thus searched for as a new identification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of managing a code identifyinga wireless device in a wireless telecommunications system, andparticularly, to such a method advantageously applicable to anultra-wide band (UWB) wireless telecommunications system.

2. Description of the Background Art

The Multi-Band Orthogonal Frequency Division Multiplexing (OFDM)Alliance (MBOA), an industrial standardization organization, establishesa standard entitled “UWB MBOA MCA (Multiple Channel Access) V0.70”,regulating that telecommunications devices communicating with each otherin a wireless telecommunications network forming a service area,referred to as an extended cluster, generate independently of each otherat random a device identification (ID), which is referred to as DEVIDand used for transmitting and receiving data. The device ID includes twooctets ranging from 0x0200 to 0xFFFF. Note that “0x” means that anumeral and/or a letter following “0x” represent a hexadecimal number.

Any of the devices when intending to participate in the wireless networkindependently generates its device identification, and transmits thedevice identification on a beacon signal along with an eight-octetdevice address AD specifically allocated in advance to the device. Inorder to prevent the device identifications thus generated fromcompeting or overlapping with each other, each device monitors thebeacon signals transmitted from the other devices. Any device, whenhaving found out that it uses the same device identification as anotherdevice, has to generate a new device identification.

The device identifications conflict or collision can be detected whenone wireless device receives a beacon signal from another device anddetermines that the same device identification as itself is included inthe beacon signal, or when beacon signals transmitted from first andsecond devices are determined by a third device as including the samedevice identification as each other.

For the former case, both of the devices, when having found thecollision or conflict, will stop using the conflicting or competingdevice identifications, and generate new device identifications. For thelatter case, the third device, when having found the collision,transmits to the first and second devices a beacon signal informing themof the collision to urge both of them to generate new deviceidentifications.

It is thus ensured that the device identification specific to eachdevice be unique throughout the wireless network in which the respectivedevices participate. The device identification may thus use not a long,eight-octet device address but a short, two-octet device identification,thereby allowing data transmission and reception.

U.S. patent application publication No. US 2005/0078646 A1 to Hong etal., teaches a method and a system that allow efficient communicationsbetween a child piconet coordinator (PNC) and a destination device. Themethod and system intend to allow a first device that belongs to aparent piconet and at the same time is the coordinator of a childpiconet (child PNC) to appropriately communicate with a second devicethat exists in the parent piconet or in the child piconet even withtheir device identifications overlapping. Hong et al., further teachesthat the method and system use an identifier for identifying thepiconets and the device identifications specifically allocated to therespective devices to generate a command frame requesting a channel timeor interval during which the first and second devices may communicatewith each other, and at the first stage, transmit the command frame tothe coordinator of the parent piconet (parent PNC), and at the secondstager allow the parent PNC to which the command frame is transmitted toallocate the channel interval during which the first and second devicesmay communicate with each other, allowing at the third stage the firstand second devices to transmit and receive data between them during thechannel interval.

The “UWB MBOA MCA V0.70” standard defines that, when the deviceidentifications conflict with each other, the conflicting deviceidentifications are refrained from being used, and each device shouldgenerate a new device identification. The standard fails, however, tospecifically define how to generate a new device identification. If ause is made of, for example, each device simply setting deviceidentifications sequentially from 0x0200 or simply incrementing deviceidentifications by one upon conflict or collision occurring, collisionswould occur more frequently, thus adversely affecting the actual datatransmitting and receiving.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a methodof managing a code with a possibility minimized in code conflict orcollision in a wireless telecommunications system.

In accordance with the present invention, in a wirelesstelecommunications system including a plurality of wireless devices,each of the plurality of wireless devices having a specific address, andindependently generating a code for identifying the wireless device,declaring the specific address and the code on a beacon signal andparticipating in a communications network, a method of managing the codecomprises: a first step of allowing one of the plurality of wirelessdevices which wishes to participate in the communications network to usea hash function based on the specific address of the one wireless deviceand a time at which the one wireless device wishes to participate togenerate a code for the one wireless device; a second step ofregistering the code for the one wireless device in association with thespecific address of the one wireless device; a third step of receiving abeacon signal transmitted from another wireless device and determiningwhether or not the code included in the signal conflicts with the codefor the one wireless device; a fourth step of storing, when said thirdstep detects a non-conflicting new code, the new code in associationwith the specific address of the other wireless device; a fifth step ofsearching, when said third step detects a conflicting code, codes storedin the one wireless device for a code that has a predeterminedrelationship with the conflicting code according to a relation inmagnitude between the specific addresses of the one wireless device andthe other wireless device; and a sixth step of updating the code for theone wireless device registered in said second step to the code that issearched for in said fifth step.

Also, in accordance with the present invention, in a wirelesstelecommunications system including a plurality of wireless devices,each of the plurality of wireless devices having a specific address,independently generating a code for identifying the wireless device,declaring the specific address and the code on a beacon signal andparticipating in a communications network, a method of managing the codecomprises: a first step of allowing one of the plurality of wirelessdevices which wishes to participate in the communications network to usea hash function based on the specific address of the one wireless deviceand a time at which the one wireless device wishes to participate togenerate a code for the one wireless device; a second step ofregistering the code for the one wireless device in association with thespecific address of the one wireless device; a third step of receiving abeacon signal transmitted from another wireless device and determiningwhether or not the code included in the signal conflicts with the codefor the one wireless device; a fourth step of storing, when said thirdstep detects a non-conflicting new code, the new code in associationwith the specific address of the other wireless device; a fifth step ofsearching, when said third step detects a conflicting code, codes storedin the one wireless device according to a relation in magnitude betweenthe specific addresses of the one wireless device and the other wirelessdevice, for an unused code that has a first relationship with theconflicting code detected in said third step when no change instructionis given for the conflicting code detected in said third step, and foran unused code that has a second relationship with the conflicting codedetected in said third step when a change instruction is given for theconflicting code detected in said third step, the second relationshipbeing opposite to the first relationship; a sixth step of updating thecode for the one wireless device registered in said second step to thecode that is searched for in said fifth step; and a seventh step ofmeasuring a period of time elapsed from the update, outputting thechange instruction until a predetermined period of time has elapsedwhich is based on a random number generated according to the specificaddress of the one wireless device, and stopping the output of thechange instruction after the period of time based on the random numberhas elapsed.

According to the present invention, one wireless device that wishes toparticipate in a communications network uses a hash function based onthe specific address of the one device and the time at which the onedevice wishes to participate to generate a specific code for the onedevice, thus providing a code that is much less likely to conflict withother codes. Also, according to the present invention, when the conflictoccurs, the relation in magnitude between the specific addresses of theone device and another wireless device may be used to search for a codethat has a predetermined relationship with the conflicting code, thusproviding a changed ore renewed code that is much less likely toconflict again with other codes.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and features of the present invention will become moreapparent from consideration of the following detailed description takenin conjunction with the accompanying drawings in which:

FIG. 1 is a schematic block diagram showing the configuration of anillustrative embodiment of a device identification manager according tothe present invention;

FIGS. 2A to 2D show how the list storage operates in the identificationmanager shown in FIG. 1; and

FIG. 3 is a schematic block diagram showing the configuration of analternative embodiment of an identification manager according to thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the accompanying drawings, illustrative embodiments ofa method of managing a code in a wireless telecommunications systemaccording to the present invention will be described in more detail.With reference to FIG. 1, the illustrative embodiment of a method ofmanaging a code according to the present invention is applied to anidentification manager 10 in a wireless telecommunications system, whichmay be specifically compliant with the “UWB MBOA MCA V0.70” standard.

The identification manager 10 includes an identification (ID) generator12 which uses a summary function such as hash function in theembodiment, and is responsive to the address specific to a relevanttelecommunications device on which the manager 10 is installed and thetime at which the device wishes to participate in the communicationsnetwork to generate a code for the relevant device. The manager 10further includes an ID register 16 adapted to register the code for therelevant device in association with the specific address of the relevantdevice, a conflict determiner 18 adapted for receiving a beacon signaltransmitted from another wireless device and determining whether or notthe code included in the signal conflicts with the code for the relevantdevice, a list updater 20 adapted for storing, when the determinationdetects a new non-conflicting code, the new code in association with thespecific address of the other wireless device, an ID searcher 22 adaptedfor searching, when the determination indicates a conflicting code,codes already stored in the relevant device for a code that has apredetermined relationship with the conflicting code according to therelation in magnitude between the specific addresses of the relevant andother wireless devices, and an ID updater 24 adapted for updating thecode for the relevant device registered in the registration operation tothe code searched for in the searching. The identification manager 10thus provides a code that is much less likely to conflict or collidedwith other codes, and also a renewed code much less likely to conflictwith other codes.

The instant illustrative embodiment is directed to the identificationmanager 10 to which a method of managing a code according to the presentinvention is applied in a wireless telecommunications system. Elementsand components not directly relating to understanding the presentinvention will be omitted from the description and illustration.

The identification manager 10 is installed in each of the wirelessdevices constituting an ultra-wide band (UWB) wirelesstelecommunications system, and has a function of managing the deviceidentification that identifies the relevant device on which it isinstalled.

The ID generator 12 has a function of generating a device identificationID, when the device intends to participate in the wireless network,independently or regardless of other devices. The ID generator 12 uses ahash function based on an eight-octet device address AD specificallyallocated in advance to the relevant device and the time generated by asystem timer, now shown, to generate a two-octet device identification.The ID generator 12 outputs the generated device identification 26 tothe ID register 16.

The list storage 14 has a function of storing therein and outputtinggenerated device identifications. The list storage 14 stores a set ofthe device address AD and the device identification ID of the device inquestion, when intending to participate in the wireless network in theorder of the device identifications. Specifically, the list storage 14has a function of using, for the respective devices, four pieces ofinformation including a previous pointer PP, the device address AD, thedevice identification ID, and a next pointer NP, and particularly usingthe previous pointer PP and the next pointer NP, to align and link thedevice identifications in ascending order.

The ID register 16 has a function of registering device identificationsin the list storage 14. The ID register 16 receives the input deviceidentification 26, and outputs a device identification 28 to the liststorage 14 as registration information. The device identification 28will sequentially be stored in the list storage 14. In the description,signals are designated with reference numbers of connections on whichthey are conveyed.

The conflict determiner 18 has a function of receiving a beacon signal30 supplied from a beacon receiver, not-shown, included in the device inquestion, the beacon signal being received from other devices by thebeacon receiver, and examining the signal to determine whether or notthe device identification of the relevant device conflicts with a deviceidentification carried on the received signal. The conflict determiner18 outputs, when a new non-conflicting device identification is found,the found device identification 32 to the list updater 20 and the IDsearcher 22.

The list updater 20 has a function of additively storing, when such anew non-conflicting device identification is found, the found deviceidentification 32 into the list storage 14. The list updater 20 is thusresponsive to a new device identification is found as non-conflicting toadditively store the found device identification 32 into the liststorage 14 as a device identification 34.

The ID searcher 22 has a function of being responsive to a conflictingdevice identification 32 supplied to read out device identifications 36stored in the list storage 14, and compare the conflicting deviceidentification 32 with the read-out device identifications 36 to searchfor an unused device identification. The ID searcher 22 starts searchingwhen supplied with the conflicting device identification 32, and outputsan unused device identification 38 searched for to the ID updater 24.

The ID updater 24 functions as updating the device identification of therelevant device to the unused device identification thus searched for.The ID updater 24 supplies the list storage 14 with the unused deviceidentification 40 searched for in order to change the current deviceidentification of the relevant device to the unused deviceidentification 40 thus searched for.

A description will now be given of the operation of the identificationmanager 10 according to the present invention additionally withreference to FIGS. 2A to 2D. Those figures are directed to the operationof device ID code management when a change does not occur in content ofthe list storage 14, i.e. no conflict occurs, and when a conflict occursthrough, for example, the generation, detection and update of deviceidentifications.

For simplicity, in FIGS. 2A to 2D, the device address AD is denoted by afour-digit decimal number and the device identification is denoted by atwo-digit decimal number. The storage location on the memory space ofthe list storage 14 is denoted by a sharp “#” followed by a number.

A description will first be given of the device identification codemanagement when no conflict occurs. When the wireless device intends toparticipate in the wireless network, the ID generator 12 uses a hashfunction based on the device address AD allocated in advance to thedevice and the time generated by the system timer to preliminarilygenerate a device identification ID.

The generated device identification ID is transmitted on a beacon signaltogether with the device address AD. The device identification 26 isgiven to the ID register 16, and stored in the list storage 14 togetherwith the device address AD in combination, as shown in FIG. 2A.Specifically, the storage location #1 stores the device address AD=0125of the relevant device and the generated device identification ID=11. Atthis time point, the device identifications of other devices are unknownand thus not stored, and the previous pointer PP and the next pointer NPare not shown.

Upon receipt of the beacon signal 30, it is detected that a device witha device address AD=1251 transmits using a device identification ID=23,and then the conflict determiner 18 determines whether or not the deviceidentification ID=23 conflicts with the device identification (ID=11) ofthe relevant device. The device identifications do not conflict witheach other in this example, and therefore the list updater 20 isstarted. The list updater 20 stores at the storage location #2 thedetected device address AD=1251 and the device identification ID=23, asshown in FIG. 2B. Because the device identification ID=23 at the storagelocation #2 is larger than the device identification ID=11 at thestorage location #1, the next pointer NP at the storage location #1 isset to pointing the location #2, and the previous pointer PP at thestorage location #2 is set to pointing the location #1.

Afterwards, a beacon signal 30 is received again. Upon this receipt, itis detected in this example that a device with a device address AD=0130is transmitting using a device identification ID=9. The conflictdeterminer 18 then determines that the device identification ID=9 doesnot conflict with the device identification of the relevant device. Thelist updater 20 stores, in response to the determination result, thedetected device address AD=0130 and the device identification ID=9 atthe storage location #3 in the list storage 14. Because the deviceidentification ID=9 at the storage location #3 is smaller than thedevice identification ID=11 at the storage location #1, the previouspointer PP at the storage location #1 is set to pointing #3 and the nextpointer NP at the storage location #3 is set to pointing #1.

Also, upon receipt of the beacon signal 30, it is detected that a devicewith a device address AD=1240 is transmitting using a deviceidentification ID=26 in this example. The conflict determiner 18 thendetermines that the device identification ID 26 does not conflict withthe device identification of the relevant device. The list updater 20stores, in response to the determination result, the detected deviceaddress AD=1240 and the device identification ID=26 at the storagelocation #4. Because the device identification ID=26 at the storagelocation #4 is larger than the device identification ID=23 at thestorage location #2, the previous pointer PP at the storage location #4is set to pointing #2 and the next pointer NP at the storage location #2is set to pointing #4. As shown in FIG. 2B, the device identification ofthe relevant device at the storage location #1 is linked with otherdevice identifications in ascending order via the previous pointer PPand the next pointer NP, thus generating an identification list.

Then, upon receipt of a further beacon signal 30, it is detected that adevice with a device address AD=0128 is transmitting using the deviceidentification ID=12. The conflict determiner 18 then determines thatthe device identification ID=12 does not conflict with the deviceidentification of the relevant device. The list updater 20 stores thedetected device address AD=0128 and the device identification ID=12 atthe storage location #5. Because the device identification ID=12intervenes between the device identification ID=11 at the storagelocation #1 and the device identification ID=23 at the storage location#2, the previous pointer at the storage location #5 is set to pointing#1 and the next pointer NP is set to pointing #2. The next pointer NP atthe storage location #1 and the previous pointer PP at the storagelocation #2 are both changed to pointing #5.

A description will be now given of the device identification codemanagement when conflict occurs. In this example, the communicationsnetwork is operated with five device identifications ID stored in thelist storage 14 as shown in FIG. 2C, and upon receipt of a beacon signal30 it is detected that a device with a device address AD=0120 istransmitting using a device identification ID=11.

The conflict determiner 18 determines that the device identificationID=11 is the same as, and hence conflicts with, the deviceidentification of the relevant device. In response to thatdetermination, the ID searcher 22 is started. The conflict determiner 18is adapted to start the ID searcher 22 also when the conflict determiner18 is informed of a conflict by the beacon signal 30 received from athird wireless device that has found that conflict.

Because the device address AD (=0125) of the relevant device is largerthan the device address AD (=0120) of the conflicting device, the IDsearcher 22 searches the list storage 14 in sequence for an unuseddevice identification that is larger than the device identification ofthe relevant device (ID=11).

The ID searcher 22 first checks the device identification ID at thestorage location #5 indicated by the next pointer NP at the storagelocation #1. The device identification ID of the storage location #5 isequal to “12”, which is next to the device identification of therelevant device, thus no unused number exists therebetween. The IDsearcher 22 then further checks the device identification ID at thestorage location #2 indicated by the next pointer NP at the storagelocation #5. The device identification ID of the storage location #2 isequal to “23”, meaning that the device identifications ranging from “13”to “22” are unused. The searcher 22 then instructs the ID updater 24 tochange the device identification of the relevant device to “13”.

The device identification ID may not necessarily be changed to “13”, butto other numbers such as “14” or “15”. Specifically, any unused numbermay be used which is larger than the conflicting number.

The ID updater 24 changes the device identification of the relevantdevice (ID=11), stored in the storage location #1, to “13”, the previouspointer PP to pointing #5, and the next pointer NP to pointing #2. Thechanged device identification is reflected to the beacon signals thatwill be transmitted thereafter. If the detection of the deviceidentifications conflicting reveals that the device address AD of therelevant device is smaller than that of the conflicting device, then theID searcher 22 searches the list storage 14 in sequence for an unuseddevice identification that is larger than the device identification ofthe relevant device. Any unused number that is smaller than theconflicting number may be selected.

The ID searcher 22 searches, when the relevant device has a largerdevice address AD than the conflicting device, the list storage 14 insequence for an unused device identification that is larger than thedevice identification of the relevant device. Alternatively, the IDsearcher 22 may be adapted to search the list storage 14 in sequence foran unused device identification which is smaller than the deviceidentification of the relevant device.

The identification manager 10 in the instant illustrative embodiment,which operates as described above, may include one or more advantages toread below. First, because the device identification is generated usinga hash function based on the device address AD of the relevant deviceand the time generated by the system timer, the generated deviceidentification is much less likely to conflict with other deviceidentifications. Second, because the generated device identification ismuch less likely to conflict with other device identifications, it ispossible to use, without searching the beacon signals 30 from otherdevices in advance for a device identification in use, the generateddevice identification to immediately participate in the wirelessnetwork. Third, two devices, when conflicting with each other, searchfor unused device identifications in opposite directions, so that thedevice identifications changed by the devices are less likely toconflict again. Fourth, even when a conflicting device modifies thedevice identification in a manner different from that described above,the device identifications changed by the two devices are less likely toconflict again.

Note that FIGS. 2A to 2D show the exemplified content of the liststorage 14. It is to be understood that any contents may be applicablewhere a set of a device address AD and a device identification ID mayoptionally be searched for in the order of device identifications.

FIG. 3 shows an alternative embodiment of the identification manager 10to which the present invention is applied. In the alternativeembodiment, the components common to those shown in FIG. 1 will bedesignated with the same reference numerals, and repetitive descriptionthereon will be omitted for simplicity.

n the alternative embodiment, the identification manager 10 includes inaddition to the components shown in FIG. 1 a timer 42 that is adapted tomeasure a period of time elapsed after a device identification ischanged due to conflict. The ID searcher 22 and ID updater 24 in thealternative embodiment have the functions described above but slightlymodified, which will be described below.

The ID updater 24 has a function of changing, according to aninstruction provided from the ID searcher 22, the device identificationof the relevant device stored in the list storage 14, and outputting astarting signal STA (44) for starting the timer 42. The timer 44 has afunction of measuring an elapsed time after the starting signal STA(STArt) (44) is given, outputting a change instruction signal CNG(ChaNGe) (46) until a predetermined period of time has elapsed that isset using a random number with the device address AD of the relevantdevice as its initial value, and stopping the output of the changeinstruction signal CNG (46) when the predetermined period of time haselapsed. The change instruction signal CNG (46) is output to the IDsearcher 22.

The ID searcher 22 is started by the conflict determiner 18, andoperates, when the change instruction signal CNG (46) is not given, inthe same way as in the illustrative embodiment shown in and describedwith reference to FIG. 1. Specifically, the ID searcher 22 searches,when the device address AD of the relevant device is larger than thedevice address AD of a conflicting device, the list storage 14 in termsof device identifications ID larger than the device identification ofthe relevant device in sequence for an unused device identification. TheID searcher 22 also searches, when the device address AD of the relevantdevice is smaller than the device address AD of the conflicting device,the device identifications ID smaller than the device identification ofthe relevant device in sequence for an unused device identification.

The ID searcher 22 also has a function of searching, when started by theconflict determiner 18 and given the change instruction signal CNG (46),device identifications ID in the opposite direction. Specifically, theID searcher 22 searches, when the device address AD of the relevantdevice is larger than the device address AD of a conflicting device, thelist storage 14 in terms of device identifications ID smaller than thedevice identification of the relevant device in sequence for an unuseddevice identification. The ID searcher 22 also searches, when the deviceaddress AD of the relevant device is smaller than the device address ADof the conflicting device, the device identifications ID larger than thedevice identification of the relevant device in sequence for an unuseddevice identification.

After a conflict occurs and the device identification of the relevantdevice is changed, if such a renewed device identification againconflicts prior to the predetermined period of time set on the timer 42expiring, then the identification manager 10 searches the unused deviceidentifications in the opposite direction for a further new deviceidentification. Except the above-stated case, the identification manager10 operates in the same way as in the illustrative embodiment shown inFIG. 1.

The identification manager 10 in the alternative embodiment thus has thefollowing further advantages in addition to the advantages involved inthe illustrative embodiment shown in FIG. 1. If the identificationmanager 10 experiences a device identification conflict repetitively ina short period of time, it is then highly possible that both of theconflicting wireless devices change device identifications according tothe same logic as each other. Thus, fifthly, the identification manager10 may switch its operative logic to be used so as to make it morepossible to prevent conflict from occurring repetitively.

In the alternative embodiment, the monitoring period of time of thetimer 42 is set using a random number based on the device address AD ofthe relevant device. Thus, sixthly, even when the same logic is used,the logic may be switched at a different time, thus making it morepossible to prevent conflict from occurring again.

Note that although the illustrative embodiments of the present inventionhave been described with respect to a device in a wirelesstelecommunications system that is compliant with the “UWB MBOA MCAV0.70” standard, the present invention is not specifically limitedthereto. The invention may be applied to any type of wirelesstelecommunications systems where each wireless device can set its deviceidentification independently of others.

The entire disclosure of Japanese patent application No. 2006-180979filed on Jun. 30, 2006, including the specification, claims,accompanying drawings and abstract of the disclosure is incorporatedherein by reference in its entirety.

While the present invention has been described with reference to theparticular illustrative embodiments, it is not to be restricted by theembodiments. It is to be appreciated that those skilled in the art canchange or modify the embodiments without departing from the scope andspirit of the present invention.

1. A method of managing a code for use in a wireless telecommunicationssystem including a plurality of wireless devices, each of the pluralityof wireless devices having a specific address, and independentlygenerating a code for identifying the wireless device, declaring thespecific address and the code on a beacon signal and participating in acommunications network, said method comprising: a first step of allowingone of the plurality of wireless devices which wishes to participate inthe communications network to use a hash function based on the specificaddress of the one wireless device and a time at which the one wirelessdevice wishes to participate to generate a code for the one wirelessdevice; a second step of registering the code for the one wirelessdevice in association with the specific address of the one wirelessdevice; a third step of receiving a beacon signal transmitted fromanother wireless device and determining whether or not the code includedin the signal conflicts with the code for the one wireless device; afourth step of storing, when said third step detects a non-conflictingnew code, the new code in association with the specific address of theother wireless device; a fifth step of searching, when said third stepdetects a conflicting code, codes stored in the one wireless device fora code that has a predetermined relationship with the conflicting codeaccording to a relation in magnitude between the specific addresses ofthe one wireless device and the other wireless device; and a sixth stepof updating the code for the one wireless device registered in saidsecond step to the code that is searched for in said fifth step.
 2. Themethod in accordance with claim 1, wherein the code having thepredetermined relationship is an unused code larger than the conflictingcode detected in said third step when the specific address of the onewireless device is larger than the specific address of the otherwireless device, and an unused code smaller than the conflicting codedetected in said third step when the specific address of the onewireless device is smaller than the specific address of the otherwireless device.
 3. The method in accordance with claim 1, wherein thecode having the predetermined relationship is an unused code smallerthan the conflicting code detected in said third step when the specificaddress of the one wireless device is larger than the specific addressof the other wireless device, and an unused code larger than theconflicting code detected in said third step when the specific addressof the one wireless device is smaller than the specific address of theother wireless device.
 4. A method of managing a code for use in awireless telecommunications system including a plurality of wirelessdevices, each of the plurality of wireless devices having a specificaddress, and independently generating a code for identifying thewireless device, declaring the specific address and the code on a beaconsignal and participating in a communications network, said methodcomprising: a first step of allowing one of the plurality of wirelessdevice which wishes to participate in the communications network to usea hash function based on the specific address of the one wireless deviceand a time at which the one wireless device wishes to participate togenerate a code for the one wireless device; a second step ofregistering the code for the one wireless device in association with thespecific address of the one wireless device; a third step of receiving abeacon signal transmitted from another wireless device and determiningwhether or not the code included in the signal conflicts with the codefor the one wireless device; a fourth step of storing, when said thirdstep detects a non-conflicting new code, the new code in associationwith the specific address of the other wireless device; a fifth step ofsearching, when said third step detects a conflicting code, codes storedin the one wireless device according to a relation in magnitude betweenthe specific addresses of the one wireless device and the other wirelessdevice, for an unused code that has a first relationship with theconflicting code detected in said third step when no change instructionis given for the conflicting code detected in said third step, and foran unused code that has a second relationship with the conflicting codedetected in said third step when the change instruction is given for theconflicting code detected in said third step, the second relationshipbeing opposite to the first relationship; a sixth step of updating thecode for the one wireless device registered in said second step to thecode that is searched for in said fifth step; and a seventh step ofmeasuring a period of time elapsed from the update, outputting thechange instruction until a predetermined period of time has elapsedwhich is based on a random number generated according to the specificaddress of the one wireless device, and stopping the output of thechange instruction after the period of time based on the random numberhas elapsed.
 5. The method in accordance with claim 4, wherein the codehaving the first relationship is a code larger than the conflicting codedetected in said third step when the specific address of the onewireless device is larger than the specific address of the otherwireless device, and a code smaller than the conflicting code detectedin said third step when the specific address of the one wireless deviceis smaller than the specific address of the other wireless device.